六、大话设计模式之工厂方法模式

GOOD：修正了简单工厂模式中不遵守开放－封闭原则。工厂方法模式把选择判断移到了客户端去实现，如果想添加新功能就不用修改原来的类，直接修改客户端即可。

源码：

//实例基类，相当于 Product（为了方便，没用抽象）
class LeiFeng
{
public:
	virtual void Sweep()
	{
		cout << "雷锋扫地" << endl;
	}
};

//学雷锋的大学生，相当于 ConcreteProduct
class Student:public LeiFeng
{
public:
	virtual void Sweep()
	{
		cout << "大学生扫地" << endl;
	}

};

//学雷锋的志愿者，相当于ConcreteProduct
class Volenter:public LeiFeng
{
public:
	virtual void Sweep()
	{
		cout << "志愿者扫地" << endl;
	}
};	

//工厂基类 Creator
class LeiFengFactory
{
public:
	virtual LeiFeng* CreateLeiFeng()
	{
		return new LeiFeng();
	}

};
 //工厂具体类
class StudentFactory :public LeiFengFactory
{
public:
	virtual LeiFeng* CreateLeiFeng()
	{
		return new Student();
	}
};
class VolenterFactory:public LeiFengFactory
{
public:
	virtual LeiFeng* CreateLeiFeng()
	{
		return new Volenter();
	}
};
 //客户端
int main()
{
	LeiFengFactory *sf = new LeiFengFactory();
	LeiFeng *s = sf->CreateLeiFeng();
	s->Sweep();
	delete s;
	delete sf;
	system("pause");
    return 0;
}

运行：